7 Sep 2011

Sputnik valve TX tests

This afternoon G6ALB and I got together to build a 2 valve 21MHz transmitter using a couple of Russian valves of the same types used in the original Sputnik 1 satellite in 1957. Surprisingly I've never built a valve transmitter before. Even today, Andrew did most of the building. My input was to wind a toroid and to help sort out the wire ends of the two valves. The valves were kindly supplied by Mike AA1TJ.  The breadboarded TX is shown in the picture. On a test this evening over the 3km path between our QTHs the 400mW TX was copied fine on my IC703 and 10m halo antenna.  Even at the lowest HT voltage (around 30V) his signal was still solid copy on the "Sputnik". Our aim is to have a pair of these units ready for Sputnik Day (Oct 4th) and to work each other and other more distant stations who are using similar rigs.  See also http://aa1tj.blogspot.com/2011/07/sputnik-qso-party-transmitter-prototype.html

9 comments:

Anonymous said...

Roger

Is there anyone In the UK that' supplies Russian valves.
Looks a really cool project.

Tony

Roger G3XBM said...

Tony, I don't know. Maybe try eBay?

Anonymous said...

Thanks Roger

Looks like a good article for Sprat

Tony

Anonymous said...

Hello,

for 'Tony':
Can send you some tubes, Mike AA1TJ
purchased same and I distributed them inside DL - one set left,
if interested please your call/adress to at yahoo.com..

Peter/DL3PB

Anonymous said...

sri, have some problems to post a comment here:
my mail adress is
'call' at yahoo.com
and yes it's free.

72/3

Peter/DL3PB

Michael, AA1TJ said...

Well done Guys...this is gonna be great fun!

Thanks, Peter, for getting back to Tony. I'm out of 21.060MHz crystals but I still have a few remaining tube sets that I'd be happy to send to prospective builders (gratis).

The final countdown to October 4 is nearly upon us, but there's still time to get your own Sputnik clone on the air; especially as we're planning to keep at it for three weeks (the amount of time that the original Sputnik-1 continued to transmit).

Thanks again Roger and Andrew for the excellent info.

Beep, beep...
Mike, AA1TJ

Anonymous said...

Very nice Roger,

I have collected my bits and pieces and through the kindness of Mike I have tubes and a crystal. Now I just need to get off my BFB and get a TX built.

I have printed off a copy of the picture of your TX and I have Mikes schematic for inspiration.

Mike is too close to me that a contact is not likely on 15 meters but I might just be able to get over to Europe.

cheers, Graham ve3gtc

Anonymous said...

Peter

The valves arrived in the midday post.
Making a start on building the transmitter in the next
Few minuites. Thank you very much for the valves and
hope to work you from October 4th.

73 Tony G4LLW

Bert, PA1B said...

Hello Roger, Thank you for the picture. It's very helpful to make the lay-out. When I received the tubes I had many questions, because I never build a transmitter with tubes.